A compound sentence is characterized by one or more than one main-clauses joined by a co-ordinating conjuction, as opposed to a complex sentence, which has a main clause together with a dependent or a subordinate clause separated by a subordinating conjunction.
A subordinate/dependent clause is defined as a clause which follows/augments a main clause, and is dependent on the main clause to make complete sense.
With this definition, shouldn't clauses joined with the main clause by illative(eg. therefore, so, consequently etc) and Alternative/Disjunctive(eg. or, either....or etc.) conjunctions be classified into subordinate clauses (assuming that commonly they are classified to be co-ordinating conjunctions)?
For example, :- "because" is classified as a subordinating conjunction, the reason being that the clause following "because", is dependent on the preceding clause to make complete sense and cannot stand on its own, and hence is a subordinating clause.
He passed because he was intelligent.
But then, the following sentence should also be a complex sentence:-
He was intelligent therefore/so/consequently he passed.
Because the clause after the conjunction depends on the preceding clause, as in the action being described in the second clause (passing) is a consequence of the action described in the preceding clause (being intelligent), the same as was in the sentence with clauses joined by "because" ("being intelligent" is linked to "passing" as a reason, or that "passing" is the consequence of "being intelligent".) What difference in the meaning or the linking of the two clauses which makes the former sentence a complex one and the latter a compound sentence.
The same is true in case of disjunctive conjunctions, where or links the action of the ensuing cause to be the consequence of the failure of the action described in the preceding clause, i.e. the action in the second clause is not independently true without the action of the preceding clause not occuring. for example:-
If you do not read, you will fail.(complex)
You must read or you will fail.(compound)
Are not the clauses in both the sentences "linked" in the same way, as far as meaning is concerned?